Liquid crystal display and manufacturing method thereof

ABSTRACT

A liquid crystal display includes a thin film transistor panel including a first alignment layer, an opposing panel including a second alignment layer, and opposite to the thin film transistor panel, and a liquid crystal layer between the thin film transistor panel and the opposing panel, and including liquid crystal molecules, wherein a difference between a pretilt angle provided by the first alignment layer and a pretilt angle provided by the second alignment layer is equal to or greater than about 0.8 degree.

This application claims priority to Korean Patent Application No.10-2013-0087491 filed on Jul. 24, 2013, and all the benefits accruingtherefrom under 35 U.S.C. §119, the entire contents of which areincorporated herein by reference.

BACKGROUND

(a) Field

The invention relates to a liquid crystal display and a manufacturingmethod thereof.

(b) Description of the Related Art

A liquid crystal display (“LCD”), which is one of the flat paneldisplays widely used presently, includes two panels on which electrodesare formed, and a liquid crystal layer interposed therebetween,generates an electric field by applying a voltage to the electrodes,rearranges liquid crystal molecules of the liquid crystal layer, andadjusts transmittance of light through the rearranged liquid crystalmolecules to display an image.

The LCD uses an alignment layer in order to arrange the liquid crystalmolecules of the liquid crystal layer in a desired direction. Further,in a case where the electric field is applied to the liquid crystallayer, in order to predetermine a direction of a movement of the liquidcrystal molecules, the liquid crystal molecules are arranged to have apretilt. In order to achieve the pretilt of the liquid crystal molecule,a method of mixing and photopolymerizing reactive mesogen in the liquidcrystal layer is known.

Recently, a size of the LCD has been increased, and in order to improveimmersion and realism for viewers, a curved display panel has beendeveloped as illustrated in FIG. 1.

SUMMARY

Since a boundary of a display panel is fixed by a sealant, when thedisplay panel is bent, buckling is generated at a center portion of apanel, and thus two panels of the display panel are misaligned. Themisalignment of the panels causes a partial deviation in the directionsof pretilts formed in the two panels in a plurality of same directions,so that a dark portion, such as texture, is generated in a pixel,thereby degrading a display quality.

The invention has been made in an effort to provide a liquid crystaldisplay (“LCD”) having an excellent display quality, and a manufacturingmethod thereof.

Further, the invention has been made in an effort to provide an LCDeffectively preventing a quality of an image from deteriorating due to adistortion of an alignment between the two panels in a curved displaypanel, and a manufacturing method thereof.

An exemplary embodiment of the invention provides a liquid crystaldisplay including a thin film transistor (“TFT”) panel including a firstalignment layer, an opposing panel including a second alignment layer,and opposite to the TFT panel, and a liquid crystal layer includingliquid crystal molecules between the TFT panel and the opposing panel,in which a difference between a pretilt angle provided by the firstalignment layer and a pretilt angle provided by the second alignmentlayer is equal to or greater than about 0.8 degree.

In the invention, a pretilt may include a direction and an angle, and apretilt direction may refer to an angle at which a long axis of a liquidcrystal molecule projected on a substrate surface is inclined based on agate line or a data line, and a pretilt angle may also refer to an angleat which the long axis of the liquid crystal molecule is inclined basedon a line vertical to a horizontal surface of the substrate.

In an exemplary embodiment, the first alignment layer and the secondalignment layer may include a same alignment material.

In an exemplary embodiment, the first alignment layer may include afirst alignment adjusting layer and a first pretilt adjusting layer, andthe second alignment layer may include a second alignment adjustinglayer and a second pretilt adjusting layer, in which the first pretiltadjusting layer defines a thin film transistor panel-side pretilt angleof the liquid crystal molecules, and the second pretilt adjusting layerdefines an opposing panel-side pretilt angle of the liquid crystalmolecules.

In an exemplary embodiment, the opposing panel-side pretilt angle by thesecond pretilt adjusting layer may be smaller than the thin filmtransistor panel-side pretilt angle by the first pretilt adjustinglayer.

In an exemplary embodiment, the first and second alignment adjustinglayers may include a polymer including a vertical alignment material,and the first and second pretilt adjusting layers include polymersincluding reactive mesogen.

In an exemplary embodiment, the TFT panel may further include a pixelelectrode including a plurality of fine branch portions, and thepolymers including the reactive mesogen of the first and second pretiltadjusting layer may be arranged in a direction of the plurality of finebranch portions.

In an exemplary embodiment, the LCD may include a curved display panelincluding the TFT panel and the opposing panel.

Another exemplary embodiment of the invention provides a method ofmanufacturing a liquid crystal display including manufacturing a TFTpanel and an opposing panel opposite to the TFT panel, applying analignment material onto each of the thin film transistor panel and theopposing panel, forming alignment layers by curing the alignmentmaterial of each of the thin film transistor panel and the opposingpanel, exposing only one of the thin film transistor panel and theopposing panel to ultraviolet rays (“UV”), forming a liquid crystallayer and bonding the thin film transistor panel and the opposing panel,and exposing the bonded panels to UV electric field.

In an exemplary embodiment, a difference between a pretilt angleprovided by the alignment layer on the TFT panel and a pretilt angleprovided by the alignment layer formed the opposing panel may be equalto or greater than about 0.8 degree.

In an exemplary embodiment, the applying an alignment material mayinclude applying a same alignment material including reactive mesogenonto each of the TFT panel and the opposing panel.

In an exemplary embodiment, the opposing panel may be exposed to the UV.

In an exemplary embodiment, the alignment layers may include analignment adjusting layer and a pretilt adjusting layer.

In an exemplary embodiment, the exposing only one of the two panels toUV may include exposing only one of the two panels to UV to UV with anintensity of approximately 5 joules per square centimeter (J/cm²) toapproximately 30 J/cm² for about 20 minutes to about 1 hour.

In an exemplary embodiment, the method may include baking the TFT paneland the opposing panel at different temperatures, respectively, beforethe forming of the liquid crystal layer and the bonding of the twopanels.

Another exemplary embodiment of the invention is to provide a method ofmanufacturing a liquid crystal display including manufacturing a TFTpanel and an opposing panel opposite to the TFT panel, applying analignment material onto each of the thin film transistor panel and anopposing panel, forming alignment layers by curing the alignmentmaterial of each of the thin film transistor panel and an opposingpanel, in which the thin film transistor panel and an opposing panel arebaked at different temperatures, respectively, forming a liquid crystallayer and bonding the thin film transistor panel and an opposing panel,and exposing the bonded panels to an UV electric field.

In an exemplary embodiment, a difference between a pretilt angleprovided by the alignment layer on the TFT panel and a pretilt angleprovided by the alignment layer formed the opposing panel may be equalto or greater than about 0.8 degree.

In an exemplary embodiment, the applying a alignment material mayinclude applying a same alignment material including reactive mesogenonto each of the TFT panel and the opposing panel.

In an exemplary embodiment, the forming the alignment layers may includedifferentiating pre-curing temperatures and/or main-curing temperaturesfor the alignment materials of the respective panels.

In an exemplary embodiment, the alignment material applied onto theopposing panel may be subjected to pre-curing at a lower temperaturethan that of the alignment material applied onto the TFT panel. In thiscase, the former may be subjected to main-curing at a higher temperaturethan or the same temperature as that of the latter.

In an exemplary embodiment, the alignment material applied onto theopposing panel may be subjected to main-curing at a higher temperaturethan that of the alignment material applied onto the TFT panel. In thiscase, the former may be subjected to pre-curing at a lower temperaturethan or the same temperature as that of the latter.

In an exemplary embodiment, the alignment layers may include analignment adjusting layer and a pretilt adjusting layer.

In an exemplary embodiment, the method may further include exposing onlyone of the two panels to UV before the forming of the liquid crystallayer and the bonding of the two panels.

According to the exemplary embodiments of the invention, even though anLCD is implemented with a curved LCD panel, it is possible to decreaseor effectively prevent a dark portion, such as a texture, on a screen.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other exemplary embodiments, advantages and features ofthis disclosure will become more apparent by describing in furtherdetail exemplary embodiments thereof with reference to the accompanyingdrawings, in which:

FIG. 1 is a diagram illustrating an exemplary embodiment of a curvedliquid crystal display (“LCD”) according to the invention.

FIG. 2 is an equivalent circuit diagram for the exemplary embodiment ofone pixel of the LCD according to the invention.

FIG. 3 is a plan view for the exemplary embodiment of one pixel of theLCD according to the invention.

FIG. 4 is a cross-sectional view taken along line III-III of the LCD ofFIG. 3.

FIG. 5 is a top plan view illustrating to the exemplary embodiment of abasic region of a pixel electrode of the LCD according the invention.

FIG. 6 is a diagram illustrating an exemplary embodiment of amisalignment of a pretilt direction due to the misalignment betweenupper and lower panels generated in the curved display panel.

FIG. 7 is a diagram illustrating a display quality according to adifference between a lower panel-side pretilt angle and an upperpanel-side pretilt angle as a simulation image.

FIG. 8 is a flowchart of the exemplary embodiment of a manufacturingmethod of the LCD according to the invention.

FIG. 9 is a flowchart of another exemplary embodiment of a manufacturingmethod of the LCD according to the invention.

FIG. 10 is a graph illustrating a pretilt angle varying according to acuring temperature of an alignment material.

DETAILED DESCRIPTION

The invention will be described more fully hereinafter with reference tothe accompanying drawings, in which exemplary embodiments of theinvention are shown. As those skilled in the art would realize, thedescribed exemplary embodiments may be modified in various differentways, all without departing from the spirit or scope of the invention.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it can be directly on the other element orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” another element, there are nointervening elements present.

It will be understood that, although the terms “first,” “second,”“third” etc. may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, “a first element,” “component,” “region,” “layer” or“section” discussed below could be termed a second element, component,region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms, including “at least one,” unless the content clearly indicatesotherwise. “Or” means “and/or.” As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. It will be further understood that the terms “comprises”and/or “comprising,” or “includes” and/or “including” when used in thisspecification, specify the presence of stated features, regions,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother element as illustrated in the Figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the Figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on “upper” sides of the other elements. The exemplary term“lower,” can therefore, encompasses both an orientation of “lower” and“upper,” depending on the particular orientation of the figure.Similarly, if the device in one of the figures is turned over, elementsdescribed as “below” or “beneath” other elements would then be oriented“above” the other elements. The exemplary terms “below” or “beneath”can, therefore, encompass both an orientation of above and below.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedexemplary embodiments. As such, variations from the shapes of theillustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, exemplary embodimentsdescribed herein should not be construed as limited to the particularshapes of regions as illustrated herein but are to include deviations inshapes that result, for example, from manufacturing. For example, aregion illustrated or described as flat may, typically, have roughand/or nonlinear features. Moreover, sharp angles that are illustratedmay be rounded. Thus, the regions illustrated in the figures areschematic in nature and their shapes are not intended to illustrate theprecise shape of a region and are not intended to limit the scope of thepresent claims.

Now, a liquid crystal display (“LCD”) according to an exemplaryembodiment of the invention will be described in detail with referenceto the accompanying drawings.

FIG. 2 is an equivalent circuit diagram for one pixel of an LCDaccording to an exemplary embodiment of the invention. A disposition ofsignal lines and pixels of the LCD according to the exemplary embodimentof the invention, and a driving method thereof will be described withreference to FIG. 2.

A pixel PX of the LCD may include a plurality of signal lines includinga gate line GL transferring a gate signal, a data line DL transferring adata signal, and a voltage dividing reference voltage line RLtransferring a voltage dividing reference voltage, first, second, andthird switching elements Qa, Qb, and Qc connected to the signal lines,and first and second liquid crystal capacitors Clca and Clcb.

The first and second switching elements Qa and Qb are connected to thegate line GL and the data line DL, respectively, and the third switchingelement Qc is connected to an output terminal of the second switchingelement Qb and the voltage dividing reference voltage line RL. The firstswitching element Qa and the second switching element Qb are threeterminal elements, such as a thin film transistor (“TFT”), and controlterminals thereof are connected with the gate line GL, and inputterminals thereof are connected with the data line DL. An outputterminal of the first switching element Qa is connected to the firstliquid crystal capacitor Clca, and an output terminal of the secondswitching element Qb is connected to input terminals of the secondliquid crystal capacitor Clcb and the third switching element Qc. Thethird switching element Qc is also a three terminal element, such as aTFT, and a control terminal thereof is connected with the gate line GL,an input terminal thereof is connected with the second liquid crystalcapacitor Clcb, and an output terminal thereof is connected with thevoltage dividing reference voltage line RL.

When a gate-on signal is applied to the gate line GL, the firstswitching element Qa, the second switching element Qb and the thirdswitching element Qc connected to the gate line GL are turned on. As aresult, a data voltage applied to the data line is applied to a firstsubpixel electrode PEa and a second subpixel electrode PEb through theturned-on first switching element Qa and second switching element Qb.Since the data voltages applied to the first subpixel electrode PEa andthe second subpixel electrode PEb are the same as each other, the firstliquid crystal capacitor Clca and the second liquid crystal capacitorClcb are charged with the same voltage value as a difference valuebetween a common voltage and the data voltage, but simultaneously, thevoltage charged in the second liquid crystal capacitor Clcb is dividedthrough the turned-on third switching element Qc. Accordingly, thevoltage charged in the second liquid crystal capacitor Clcb is decreasedby a difference between the common voltage and the voltage dividingreference voltage.

The voltage charged in the first liquid crystal capacitor Clca and thevoltage charged in the second liquid crystal capacitor Clcb are changed,so that inclined angles of liquid crystal molecules in the firstsubpixel and the second subpixels are different, and thus luminancebetween the two subpixels is different. When the voltage of the firstliquid crystal capacitor Clca and the voltage of the second liquidcrystal capacitor Clcb are appropriately adjusted, an image viewed froma side can be maximally close to an image viewed from a front side,thereby improves side visibility.

In the illustrated exemplary embodiment, the pixel PX includes thesecond liquid crystal capacitor Clcb and the third switching element Qcconnected to the voltage dividing reference voltage line RL in order tomake the voltage charged in the first liquid crystal capacitor Clca andthe voltage charged in the second liquid crystal capacitor Clcb bedifferent from each other, but may be differently configured dependingon an exemplary embodiment. In an exemplary embodiment, the secondliquid crystal capacitor Clcb may be connected to a step-down capacitor,for example. Particularly, the pixel PX may include the third switchingelement Qc including a first terminal connected to a step-down gateline, a second terminal connected to the second liquid crystal capacitorClcb, and a third terminal connected to the step-down capacitor, so thatsome of an amount of charges charged in the second liquid crystalcapacitor Clcb is charged in the step-down capacitor and thus thecharged voltages of the first liquid crystal capacitor Clca and thesecond liquid crystal capacitor Clcb may be differently set from eachother. In another exemplary embodiment, the first liquid crystalcapacitor Clca and the second liquid crystal capacitor Clcb may beconnected to different data lines, so as to receive different datavoltages, respectively, so that the charged voltages of the first liquidcrystal capacitor Clca and the second liquid crystal capacitor Clcb maybe differently set from each other.

A structure of the LCD according to the exemplary embodiment illustratedin FIG. 2 will be described with reference to FIGS. 3 to 5. FIG. 3 is aplan view illustrating an exemplary embodiment of one pixel of the LCDaccording to the exemplary embodiment of the invention, and FIG. 4 is across-sectional view taken along line III-III of the LCD of FIG. 3. FIG.5 is a top plan view illustrating a basic region of a pixel electrode ofthe LCD according to the exemplary embodiment of the invention.

First, referring to FIGS. 3 and 4, the LCD according to the exemplaryembodiment includes a lower panel 100 and an upper panel 200 facing eachother, a liquid crystal layer 3 interposed between the lower and upperpanels 100 and 200, and a pair of polarizers (not illustrated) attachedto external surfaces of the lower and upper panels 100 and 200.

First, the lower panel 100 will be described.

A gate conductor including a gate line 121 and a voltage dividingreference voltage line 131 is disposed on an insulation substrate 110including transparent glass or plastic. The gate line 121 includes afirst gate electrode 124 a, a second gate electrode 124 b, a third gateelectrode 124 c and a wide end portion (not illustrated) for connectingwith another layer or an external driving circuit. The voltage dividingreference voltage line 131 includes first storage electrodes 135 and 136and a reference electrode 137. Further, second storage electrodes 138and 139, which are not connected with the voltage dividing referencevoltage line 131 but overlap the second subpixel electrode 191 b, arealso provided.

A gate insulation layer 140 is disposed on the gate line 121 and thevoltage dividing reference voltage line 131, and a first semiconductor154 a, a second semiconductor 154 b and a third semiconductor 154 c aredisposed on the gate insulation layer 140. A plurality of ohmic contacts163 a, 165 a, 163 b, 165 b, 163 c, and 165 c is disposed on thesemiconductors 154 a, 154 b and 154 c.

A data conductor including a plurality of data lines 171 including afirst source electrode 173 a and a second source electrode 173 b, afirst drain electrode 175 a, a second drain electrode 175 b, a thirdsource electrode 173 c and a third drain electrode 175 c is disposed onthe ohmic contacts 163 a, 165 a, 163 b, 165 b, 163 c and 165 c and thegate insulation layer 140. The data conductor and the semiconductors andthe ohmic contacts disposed under the data conductor may besimultaneously provided by using one mask. The data line 171 includes awide end portion (not illustrated) for connecting with another layer oran external driving circuit.

The first gate electrode 124 a, the first source electrode 173 a, andthe first drain electrode 175 a provide the first TFT Qa together with afirst semiconductor 154 a, and a channel of the TFT is disposed on thesemiconductor 154 a between the first source electrode 173 a and thefirst drain electrode 175 a. Similarly, the second gate electrode 124 b,the second source electrode 173 b and the second drain electrode 175 bprovide the second TFT Qb together with a second semiconductor 154 b,and a channel thereof is disposed on the semiconductor 154 b between thesecond source electrode 173 b and the second drain electrode 175 b. Thethird gate electrode 124 c, the third source electrode 173 c and thethird drain electrode 175 c provide the third TFT Qb together with athird semiconductor 154 c, and a channel is disposed on thesemiconductor 154 c between the third source electrode 173 c and thethird drain electrode 175 c. The second drain electrode 175 b isconnected with the third source electrode 173 c, and includes a widelyexpanded portion 177.

A first passivation layer 180 p is disposed on the data conductors 171,173 c, 175 a, 175 b, and 175 c, and exposed portions of thesemiconductors 154 a, 154 b, and 154 c. In an exemplary embodiment, thefirst passivation layer 180 p may include an inorganic insulation layer,such as silicon nitride or silicon oxide. The first passivation layer180 p may effectively prevent a pigment of a color filter 230 fromflowing in the exposed portions of the semiconductors 154 a, 154 b and154 c.

The color filter 230 is disposed on the first passivation layer 180 p.The color filter 230 is extended in a vertical direction along adjacenttwo data lines.

A second passivation layer 180 q is disposed on the color filter 230. Inan exemplary embodiment, the second passivation layer 180 q may includean inorganic insulation layer, such as silicon nitride or silicon oxide.The second passivation layer 180 q effectively prevents the color filter230 from being lifted up and suppresses a contamination of the liquidcrystal layer 3 due to an organic material, such as a solvent, flowingin from the color filter 230, thereby effectively preventing a defect,such as an afterimage, which may be caused during the driving of ascreen.

The first passivation layer 180 p and the second passivation layer 180 qare provided with a first contact hole 185 a and a second contact hole185 b, through which the first drain electrode 175 a and the seconddrain electrode 175 b are exposed. The first passivation layer 180 p,the second passivation layer 180 q, and the gate insulation layer 140are provided with a third contact hole 185 c, through which a part ofthe reference electrode 137 and a part of the third drain electrode 175c are exposed, and a connection member 195 covers the third contact hole185 c. The connecting member 195 electrically connects the referenceelectrode 137 and the third drain electrode 175 c exposed through thethird contact hole 185 c.

A plurality of pixel electrodes 191 is disposed on the secondpassivation layer 180 q. The respective pixel electrodes 191 areseparated from each other with the gate line 121 interposedtherebetween, and include first subpixel electrode 191 a and secondsubpixel electrode 191 b adjacent in a column direction based on thegate line 121. In exemplary embodiments, the pixel electrode 191 mayinclude a transparent conductive material, such as indium tin oxide(“ITO”) and indium zinc oxide (“IZO”), or may include a reflectivemetal, such as aluminum, silver, chromium, and an alloy thereof.

Each of the first subpixel electrode 191 a and the second subpixelelectrode 191 b include one or more basic electrodes illustrated in FIG.5 or modifications of the basic electrode.

The first subpixel electrode 191 a and the second subpixel electrode 191b are physically and electrically connected with the first drainelectrode 175 a and the second drain electrode 175 b through the firstcontact hole 185 a and the second contact hole 185 b, respectively, andreceives the data voltage from the first drain electrode 175 a and thesecond drain electrode 175 b. Some of the data voltage applied to thesecond drain electrode 175 b is divided through the third sourceelectrode 173 c, so that a magnitude of the voltage applied to the firstsubpixel electrode 191 a is larger than a magnitude of the voltageapplied to the second subpixel electrode 191 b.

The first subpixel electrode 191 a and the second subpixel electrode 191b, to which the data voltage is applied, generate an electric fieldtogether with a common electrode 270 of the upper panel 200 to bedescribed below so as to determine a direction of the liquid crystalmolecule of the liquid crystal layer 3 between the two electrodes 191and 270. Luminance of light passing through the liquid crystal layer 3is changed according to the determined direction of the liquid crystalmolecule as described above.

A lower alignment layer 11 is disposed on the pixel electrode 191. Thelower alignment layer 11 includes an alignment adjusting layer 11 a anda pretilt adjusting layer 11 b.

The alignment adjusting layer 11 a includes a polymer including avertical alignment material. In an exemplary embodiment, the alignmentadjusting layer 11 a may be a polymer including a dianhydride-basedmonomer, such as an alicyclic dianhydride-based monomer, for example, adiamine-based monomer, such as an aromatic diamine-based monomer and analiphatic ring substituted aromatic diamine-based monomer, for example,and an aromatic epoxide-based monomer that is a crosslinker. In anexemplary embodiment, the alignment adjusting layer 11 a may include atleast one of polymer-based materials, such as polyamide, polyamic acid,polysiloxane, nylon, polyvinylalcohol (“PVA”), and polyvinyl chloride(“PVC”), for example.

The pretilt adjusting layer 11 b includes a polymer in which thevertical alignment material and a monomer including reactive mesogen(“RM”) are chemically bonded to each other. In exemplary embodiments,the polymer included in the pretilt adjusting layer 11 b may include adianhydride-based monomer, such as an alicyclic dianhydride-basedmonomer, for example, and a diamine-based monomer, such as a photoactivediamine-based monomer, an alkylated aromatic diamine-based monomer andan aromatic diamine-based monomer, for example.

The photoactive diamine-based monomer of the polymer is a monomerincluding reactive mesogen, and serves to determine a direction of thepretilt of the pretilt adjusting layer 11 b of the lower alignment layer11. In an exemplary embodiment, the polymer of the alignment adjustinglayer 11 and the polymer including the RM of the pretilt adjusting layer11 b may be chemically bonded to each other.

The RM is a material which is photo-cured by light such as ultravioletrays (“UV”), for example, to limit the pretilt to one direction. In anexemplary embodiment, the RM may be a compound expressed by a formulabelow.

P1-A1-(Z1-A2)_(n)-P2,

where P1 and P2 are independently selected from acrylate, methacrylate,vinyl, vinyloxy and epoxy groups, A1 and A2 are independently selectedfrom 1,4-phenylene and naphthalene-2,6-diyl groups, Z1 is one of COO—,OCO— and a single bond, and n is one of 0, 1 and 2.

In further detail, a compound expressed as one of the next equations canbe exemplified.

Here, P1 and P2 are independently selected from acrylate, methacrylate,vinyl, vinyloxy, or epoxy groups, for example.

Now, the upper panel 200 will be described.

A light blocking member 220 is disposed on an insulation substrate 210.The light blocking member 220 is also referred to as a black matrix, andeffectively prevents a leakage of light. A plurality of openings (notillustrated) facing the pixel electrodes 191 is defined in the lightblocking member 220 having almost the same shape as that of the pixelelectrode 191 The light blocking member 220 effectively prevents aleakage of light between the pixel electrodes 191. The light blockingmember 220 may include a portion corresponding to the gate line 121 andthe data line 171, and a portion corresponding to the TFT. Depending onan exemplary embodiment, the light blocking member 220 may be disposedonly on the lower panel 100, or may be disposed on both the upper andlower panels 100 and 200.

An overcoat 250 is disposed on the light blocking member. The overcoat250 may include an organic insulating material, and provides a flatsurface. Depending on an exemplary embodiment, the overcoat 250 may beomitted.

The common electrode 270 is disposed on the overcoat 250. The commonelectrode 270 may include a transparent conductor, such as ITO and IZO.

An upper alignment layer 21 is disposed on the common electrode 270.Similar to the lower alignment layer 11, the upper alignment layer 21includes an alignment adjusting layer 21 a and a pretilt adjusting layer21 b. Detailed configurations of the alignment adjusting layer 21 a andthe pretilt adjusting layer 21 and a relationship therebetween may bethe same as those described in the lower alignment layer 11. The upperalignment layer 21 may include the same material as that of the loweralignment layer 11. In a case where the upper and lower alignment layers21 and 11 include different materials each other, many problems, such asan afterimage, for example, may be caused. However, even though theupper alignment layer 21 and the lower alignment layer 11 include thesame material, the angles of the pretilts provided by the alignmentadjusting layer 21 a of the upper alignment layer 21 and the alignmentadjusting layer 11 a of the lower alignment layer 11 may be differentfrom each other.

The liquid crystal layer 3 includes a plurality of liquid crystalmolecules 31, and the liquid crystal molecule 31 are aligned to bevertical to the surfaces of the two substrates 110 and 210 in a statewhere a voltage is not applied to the two electric field generatingelectrodes 191 and 270, and are aligned to have a pretilt inclined inthe same direction as a longitudinal direction of a cutout pattern ofthe pixel electrode 191. The liquid crystal molecules 31 may bevertically aligned by the vertical alignment materials within the loweralignment layer 11 and the upper alignment layer 21, and the pretilts ofthe liquid crystal molecules 31 may be adjusted by the pretilt adjustinglayer 11 b of the lower alignment layer 11 and the pretilt adjustinglayer 21 b of the upper alignment layer 21.

The pretilt angles of the liquid crystal molecules 31 may be dividedinto a lower panel-side pretilt angle by the pretilt adjusting layer 11b of the lower alignment layer 11, and an upper panel-side pretilt angleby the pretilt adjusting layer 21 b of the upper alignment layer 21, andthe lower panel-side pretilt angle and the upper panel-side pretiltangle are different from each other. In an exemplary embodiment, thedifference in the angle may be approximately 0.8 degrees or more, andthe upper panel-side pretilt angle may be smaller than the lowerpanel-side pretilt angle.

A basic electrode of the pixel electrode 191 will be described withreference to FIG. 5.

As shown in FIG. 5, an entire shape of the basic electrode is aquadrangle, and includes a cross-shaped stem portion including ahorizontal stem portion 193 and a vertical stem portion 192 orthogonalto the horizontal stem portion 193. Further, the basic electrode isdivided into a first sub region Da, a second sub region Db, a third subregion Dc and a fourth sub region Dd by the horizontal stem portion 193and the vertical stem portion 192, and the first to fourth sub regionsDa, Db, D, and Dd include a plurality of first fine branch portions 194a, a plurality of second fine branch portions 194 b, a plurality ofthird fine branch portions 194 c and a plurality of fourth fine branchportions 194 d, respectively.

The first fine branch portion 194 a is obliquely extended in a leftupper direction from the horizontal stem portion 193 or the verticalstem portion 192, and the second fine branch portion 194 b is obliquelyextended in a right upper direction from the horizontal stem portion 193or the vertical stem portion 192. The third fine branch portion 194 c isobliquely extended in a left lower direction from the horizontal stemportion 193 or the vertical stem portion 192, and the fourth fine branchportion 194 d is obliquely extended in a right lower direction from thehorizontal stem portion 193 or the vertical stem portion 192.

The first to fourth fine branch portions 194 a, 194 b, 194 c, and 194 dform approximately 45 degrees or 135 degrees with respect to the gatelines 121 a and 121 b or the horizontal stem portion 193. Further, thefine branch portions 194 a, 194 b, 194 c, and 194 d of adjacent two subregions of the first to fourth sub regions Da, Db, Dc, and Dd may beorthogonal to each other.

Widths of the fine branch portions 194 a, 194 b, 194 c, and 194 d may beabout 2.5 micrometers (μm) to about 5.0 μm, and an interval between thefine branch portions 194 a, 194 b, 194 c, and 194 d adjacent within onesub region Da, Db, Dc, or Dd may be about 2.5 μm to about 5.0 μm. Thewidths and the intervals may be taken in a direction substantiallyperpendicular to a direction in which the branch portion extends (e.g.,longitudinal direction).

According to the exemplary embodiment of the invention, the widths ofthe fine branch portions 194 a, 194 b, 194 c and 194 d may increase asbeing close to the horizontal stem portion 193 or the vertical stemportion 192, and a difference between a portion having the largest widthand a portion having the smallest width in one fine branch portion 194a, 194 b, 194, or 194 d may be about 0.2 μm to about 1.5 μm.

The first subpixel electrode 191 a and the second subpixel electrode 191b are connected with the first drain electrode 175 a or the second drainelectrode 175 b through the first contact hole 185 a and the secondcontact hole 185 b, and receives a data voltage from the first drainelectrode 175 a and the second drain electrode 175 b. In this case,sides of the first to fourth fine branch portions 194 a, 194 b, 194 c,and 194 d distort the electric field to create horizontal componentsdetermining a direction of the inclination of the liquid crystalmolecules 31. The horizontal components of the electric field are almosthorizontal to the sides of the first to fourth fine branch portions 194a, 194 b, 194 c, and 194 d. Accordingly, as illustrated in FIG. 5, theliquid crystal molecules 31 are inclined in a direction parallel to thelongitudinal direction of the fine branch portions 194 a, 194 b, 194 c,and 194 d. The pixel electrode 191 includes the four sub regions Da toDd in which the longitudinal directions of the fine branch portions 194a, 194 b, 194 c, and 194 d are different from each other, so that thedirections, in which the liquid crystal molecules 31 are inclined, areapproximately four directions, and four domains in which the alignmentdirections of the liquid crystal molecules 31 are different from eachother are disposed on the liquid crystal layer 3. As described above,when varying the directions in which the liquid crystal molecules areinclined, a reference viewing angle of the LCD is increased.

Now, deterioration in display quality generable in the curved LCD willbe described with reference to FIG. 6. FIG. 6 is a diagram illustratingan exemplary embodiment of a misalignment of a pretilt direction due tothe misalignment between the upper and lower panels generated in thecurved display panel.

Referring to FIGS. 4 and. 5 together, the liquid crystal molecule 31 ofthe liquid crystal layer 3 are aligned to have a pretilt inclined in thesame direction as the longitudinal direction of a cutout pattern of thepixel electrode 191 in a state where an electric field is not applied,and for the pretilt of the liquid crystal molecules 31, the pretiltadjusting layers 11 b and 21 b disposed on the alignment layers 11 and21 of the lower and upper panels 100 and 200 have the pretilt inclinedin the same direction as the cutout pattern of the pixel electrode 191.

The pretilts of the pretilt adjusting layers 11 b and 21 b are providedin the same direction at a position at which the lower panel 100 and theupper panel 200 face each other, which may be expressed with analignment state illustrated in a left drawing of FIG. 6. However, whenthe display panel is bent in order to provide the curved display panel,the alignment between the lower panel and the upper panel is distorted,and as a result, like a portion indicated with a dotted-line quadrangleof a right drawing of FIG. 6, there occurs a region in which thedirection of the pretilt of the pretilt adjusting layer 11 b of thelower panel 100 is misaligned with the direction of the pretilt of thepretilt adjusting layer 21 b of the upper panel 200. A problem in thedirection in which the liquid crystal molecules 31 are inclined isgenerated in the region, so that a texture is generated in the screen.According to the invention, in a case where the pretilt angle by thelower pretilt adjusting layer 11 b and the pretilt angle by the upperpretilt adjusting layer 21 b are differently provided from each other,it is possible to decrease or effectively prevent a generation of thetexture generated on the screen.

FIG. 7 is a diagram illustrating a display quality according to adifference between the lower panel-side pretilt angle and the upperpanel-side pretilt angle as a simulation image.

In FIG. 7, a voltage of 4 V is applied to five pairs of pixelspositioned in an upper line, and a voltage of 8 V is applied to fivepairs of pixels positioned in a lower line. In one pair of pixels ineach line, a left side is a state in which an upper panel-side pretiltdirection and a lower panel-side pretilt direction are aligned, and aright side is a state in which the upper panel-side pretilt directionand the lower panel-side pretilt direction are misaligned by 30 μm. Adisplay state was simulated while gradually decreasing the upperpanel-side pretilt angle from 1 degree to 0 degree in a state where thelower panel-side pretilt angle is fixed at 1 degree.

It can be seen that in both the upper and lower lines, as the upperpanel-side pretilt angle is decreased, the generation of the texture isgradually weak, and when the pretilt angle is 0.2 degree, the texture israrely generated, and when the pretilt angle is 0 degree, the texturecompletely disappears. A result of the simulation in the curved displaypanel for transmittance and luminance variation is represented in Table1 below.

TABLE 1 Pretilt (degree) Transmittance Simulation (a.u.) Lower Upper 30μm Luminance panel panel Delta Aligned Misaligned variation (%) 1.0 01.0 0.17072 0.17072 0.0 0.2 0.8 0.17191 0.16988 −1.2 0.5 0.5 0.173390.16651 −4.0 0.8 0.2 0.17459 0.1625 −6.9 1 0.0 0.17527 0.15955 −9.0

Referring to Table 1, the delta represents a difference between theupper panel-side pretilt angle and the lower panel-side pretilt angle,and the transmittance simulation is measured in absorbance unit (a.u.).As represented in Table 1, when the lower panel and the upper panel aremisaligned under a condition that both the lower panel-side pretiltangle and the upper panel-side pretilt angle are 1 degree, luminance isapproximately decreased by 9 percent (%). When a difference between thepretilt angles is 0.8 degree or more, even though the alignment isdistorted, luminance deviation is decreased to a level underapproximately 1.2%, and when a difference between the pretilt angles isapproximately 1 degree, the luminance deviation is 0.

Now, exemplary embodiments in which the alignment layer is provided soas to have a difference between the lower panel-side pretilt angle andthe upper panel-side pretilt angle will be described with reference toFIGS. 8 to 10.

FIG. 8 is a flowchart of a manufacturing method of the LCD according tothe exemplary embodiment of the invention.

As illustrated in FIG. 8, first, a lower panel and an upper panel aremanufactured (S1). Here, the manufacturing of the lower panel meansmanufacturing a TFT panel, except for a lower alignment layer. In anexemplary embodiment, the lower panel is manufactured by providing thegate conductor, the data conductor, the TFT, the color filter, the pixelelectrode, and the like, which are disposed on the insulating substrateas described with reference to FIGS. 2 to 5. The manufacturing of theupper panel means manufacturing an opposing panel, except for an upperalignment layer, as an opposing panel of the TFT panel. In an exemplaryembodiment, the upper panel is provided by providing a light blockingmember, a common electrode, and the like on the insulating substrate.Depending on an exemplary embodiment, the light blocking member may bedisposed only on the lower panel, or may be disposed on both the upperand lower panels.

Next, an alignment material including RM is applied onto the lower paneland the upper panel manufactured as described above (S2). Theapplication of the alignment material may be performed by a method, suchas inkjet printing and roll printing. In an exemplary embodiment, thealignment material applied onto the lower panel and the upper panel maybe the same as each other. In an exemplary embodiment, the alignmentlayer is the same as that of the description given in relation to thealignment layer.

Next, an alignment layer including an alignment adjusting layer and apretilt adjusting layer is provided by curing the alignment materialapplied onto each panel (S3). The curing of the alignment material mayinclude pre-curing at a low temperature and main-curing at a hightemperature.

The pre-curing is to heat the alignment material at, for example,approximately 70 degrees Celsius (° C.) to approximately 100° C., and asolvent of the alignment material is evaporated, and a combinationwithin the alignment material is phase-separated by the pre-curing. Thephase-separation is generated by a difference in a polarity ofcomponents within the alignment material, and a material having arelatively large polarity moves to a surrounding area of the electrode,and a material having a relatively small polarity moves above thesurrounding area.

The main-curing is heating the alignment material at, for example,approximately 200° C. to approximately 250° C., and stacks the alignmentlayer, in which a material having a relatively large polarity, forexample, a polymer layer providing the alignment adjusting layer, isdisposed at a lower side, and a material having a relatively smallpolarity, for example, a polymer layer providing the pretilt adjustinglayer, is disposed at an upper side. As described above, the polymerproviding the pretilt adjusting layer is a polymer in which a monomerincluding RM is bonded to another monomer.

Next, only the upper panel is exposed to UV (S4). Accordingly, a part orthe entirety of RM of the alignment layer disposed on the upper panel isphoto-cured in a state where the pretilt is not provided. Accordingly,in the alignment layer of the upper panel, the amount of reactivemesogen, which is not photo-cured, arranged in the same direction asthose of the liquid crystal molecules to form the pretilt during theexposure to a UV electric field later is decreased. The UV exposure maybe continued for about 20 minutes to about 1 hour with an intensity ofapproximately 5 joules per square centimeter (J/cm²) to approximately 30J/cm², but is not limited thereto. Depending on an exemplary embodimentof the invention, the UV exposure may be performed only on the lowerpanel, not the upper panel.

Next, a liquid crystal layer is provided and the two panels are bondedto each other (S5). The forming of the liquid crystal layer may beperformed before or after the bonding of the two panels. That is, liquidcrystals are dropped onto any one panel by a method, such as inkjetprinting, and then the other panel may be bonded to the one panel, andthe two panels are bonded to each other and then liquid crystal may beinjected through an injection opening between the two panels.

Next, the bonded panels are exposed to an ultraviolet ray electric field(S6). Here, as well known to those skilled in the art, the exposure tothe UV electric field means changing an alignment so that the liquidcrystal molecules have pretilts in a desired direction and angle byapplying an electric field to the liquid crystal, and irradiating UV ina state where compounds including RM are arranged in the same directionas those of the liquid crystal molecules. When the UV are irradiatedonto the compounds including RM arranged in the same direction as thoseof the liquid crystal molecules, RM is photo-cured. Accordingly, thecompounds including RM of the pretilt adjusting layer is cured in astate of being arranged in the same direction as those of the liquidcrystal molecules in a surrounding area.

However, the upper panel is already exposed to the UV in an operationS4, so that at least some of the RM of the upper panel is photo-cured.Accordingly, even though the panels are bonded and then are exposed tothe UV electric field, the reactive mesogen, which is arranged in thesame direction as those of the liquid crystal molecules to bephoto-cured, may be less than that of the lower panel or may rarelyexist. Accordingly, the pretilt by the pretilt adjusting layer of theupper panel is smaller than the pretilt by the pretilt adjusting layerof the lower panel, so that a difference between the pretilt angles ofthe upper panel and the lower panel may be created.

FIG. 9 is a flowchart of a manufacturing method of the LCD according toanother exemplary embodiment of the invention, and FIG. 10 is a graphillustrating a pretilt angle varying according to a curing temperatureof an alignment material.

The exemplary embodiment of FIG. 9 is similar to the exemplaryembodiment of FIG. 8, but is different from the exemplary embodiment ofFIG. 8 in terms of an operation of forming the alignment layer by curingthe alignment material, and does not include an operation of exposingonly the upper panel to UV.

Particularly, first, a lower panel and an upper panel are manufactured(S1), and then an alignment material including RM is applied onto thelower panel and the upper panel (S2).

Next, an alignment layer including an alignment adjusting layer and apretilt adjusting layer is provided by curing the alignment materialapplied onto each panel by differentiating a baking temperature of eachpanel (S3). In the applied alignment material, the amount of remainingRM which may be involved in forming the pretilt during the exposure toan UV electric field later, is changed according to the bakingtemperature for curing the alignment material. Accordingly, liquidcrystal molecules of the liquid crystal layer disposed between thepanels baked at the different temperature conditions may be arranged tohave different panel-side pretilt angles. A difference in the backingtemperature of each panel may mean a difference in a pre-curingtemperature and/or a difference in a main-curing temperature for thealignment material of each panel.

Although it is not theoretically limited, in a case where the pre-curingtemperature is relatively high, the RM may be better phase-separated,and in a case where the main-curing temperature is relatively high, RMmay be decomposed by thermal reaction. The former case means an increasein the amount of RM involved in the pretilt, and the latter case meansan opposite case.

The graph of FIG. 10 represents the pretilt angle of the liquid crystalmolecules in a case where the alignment layer is provided while varyingthe pre-curing temperature and the main-curing temperature, and then theexposure to the UV electric field is performed on the alignment layerunder the same condition. In the graph, a horizontal axis representscuring temperatures (M: main-curing temperature, P: pre-curingtemperature), and a vertical axis represents a pretilt angle (however,herein, values marked on the vertical axis are angles inclined based ona horizontal surface of the substrate, accordingly, the pre-tilt angleis represented by subtracting the angle indicated in the graph from 90degrees, i.e., 90° minus the angle indicated in the graph). In thegraph, boxes and vertical lines connected to a top line and a bottomline of each of the boxes represent quartiles. The bottom line, a middleline, and the top line of each of the boxes indicate first, second, andthird quartiles of data set, respectively. The values above or below theboxes indicate the second quartile, which is the median of the data. Endpoints of the vertical lines connected to the top line and the bottomline of each of the boxes indicate the highest and lowest values of thedata set, respectively.

It can be seen that in a case where the pre-curing temperature isrelatively higher, and the main-curing temperature is relatively lower(e.g., a second data from a left side of the horizontal axis), thepretilt angle is larger. Even though the alignment material is subjectedto the pre-curing at the same temperature, in a case where themain-curing temperature is lower, the pretilt angle is larger.Similarly, even though the alignment material is subjected to themain-curing at the same temperature, in a case where the pre-curingtemperature is higher, the pretilt angle is larger. As described above,the alignment layer is provided by differentiating the bakingtemperature of each panel, so that each panel-side pretilt angle of theliquid crystal molecules may be differently set later.

Next, a liquid crystal layer is provided and the two panels are bondedto each other (S4). The liquid crystal layer may be provided by droppingliquid crystals before the bonding of the panels or injecting liquidcrystals after the bonding of the panels.

Next, the bonded panels are exposed to an UV electric field (S5), and RMis photo-cured in a state where compounds including the RM of thealignment layer are arranged in the same direction as those of theliquid crystal molecules. As described above, since the amount ofreactive mesogen, which is photo-curable in the direction in which theliquid crystal molecules are arranged by the exposure to the UV electricfield in the alignment layer of each panel may be different due to adifference in the baking temperature, a lower panel-side pretilt angleand an upper panel-side pretilt angle may be differently provided fromeach other.

The exemplary embodiment of FIG. 8 and the exemplary embodiment of FIG.9 may be combined and performed. In an exemplary embodiment, after thealignment layer is provided by differentiating the backing temperatureof each panel, UV may be irradiated to only one panel before the bondingof the two panels (or before the forming of the liquid crystal layerdepending on a case).

While this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosed exemplaryembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A liquid crystal display, comprising: a thin filmtransistor panel including a first alignment layer; an opposing panelincluding a second alignment layer, and opposite to the thin filmtransistor panel; and a liquid crystal layer between the thin filmtransistor panel and the opposing panel, and including liquid crystalmolecules; wherein a difference between a pretilt angle provided by thefirst alignment layer and a pretilt angle provided by the secondalignment layer is equal to or greater than about 0.8 degree.
 2. Theliquid crystal display of claim 1, wherein: the first alignment layerand the second alignment layer include a same alignment material.
 3. Theliquid crystal display of claim 2, wherein: the first alignment layerincludes a first alignment adjusting layer and a first pretilt adjustinglayer, and the second alignment layer includes a second alignmentadjusting layer and a second pretilt adjusting layer, wherein the firstpretilt adjusting layer defines a thin film transistor panel-sidepretilt angle of the liquid crystal molecules, and the second pretiltadjusting layer defines an opposing panel-side pretilt angle of theliquid crystal molecules.
 4. The liquid crystal display of claim 3,wherein: the opposing panel-side pretilt angle is smaller than the thinfilm transistor panel-side pretilt.
 5. The liquid crystal display ofclaim 3, wherein: the first and second alignment adjusting layersinclude a polymer including a vertical alignment material, and the firstand second pretilt adjusting layers include polymers including reactivemesogen.
 6. The liquid crystal display of claim 5, wherein: the thinfilm transistor panel further includes a pixel electrode including aplurality of fine branch portions, and the polymers including thereactive mesogen of the first and second pretilt adjusting layers arearranged in a direction of the plurality of fine branch portions.
 7. Theliquid crystal display of claim 1, further comprising: a curved displaypanel including the thin film transistor panel and the opposing panel.8. A method of manufacturing a liquid crystal display, the methodcomprising: manufacturing a thin film transistor panel, and an opposingpanel opposite to the thin film transistor panel; applying an alignmentmaterial onto each of the thin film transistor panel and the opposingpanel; forming alignment layers by curing the alignment material of eachof the thin film transistor panel and the opposing panel; exposing onlyone of the thin film transistor panel and the opposing panel toultraviolet rays; forming a liquid crystal layer and bonding the thinfilm transistor panel and the opposing panel; and exposing the bondedpanels to an ultraviolet ray electric field.
 9. The method of claim 8,wherein: a difference between a pretilt angle provided by the alignmentlayer on the thin film transistor panel and a pretilt angle provided bythe alignment layer on the opposing panel is equal to or greater thanabout 0.8 degree.
 10. The method of claim 9, wherein: the applying thealignment material includes applying a same alignment material includingreactive mesogen onto each of the thin film transistor panel and theopposing panel.
 11. The method of claim 10, wherein: the opposing panelis exposed to the ultraviolet rays.
 12. The method of claim 10, wherein:the alignment layers include an alignment adjusting layer and a pretiltadjusting layer.
 13. The method of claim 10, wherein: the exposing onlyone of the thin film transistor panel and the opposing panel toultraviolet rays includes exposing only one of the thin film transistorpanel and the opposing panel to ultraviolet rays with an intensity ofapproximately 5 joules per square centimeter to approximately 30 joulesper square centimeter for about 20 minutes to about 1 hour.
 14. Themethod of claim 10, further comprising: baking the thin film transistorpanel and the opposing panel at different temperatures, respectively,before the forming the liquid crystal layer and the bonding of the thinfilm transistor panel and the opposing panel.
 15. A method ofmanufacturing a liquid crystal display, the method comprising:manufacturing a thin film transistor panel, and an opposing panelopposite to the thin film transistor panel; applying an alignmentmaterial onto each of the thin film transistor panel and the opposingpanel; forming alignment layers by curing the alignment material of eachof the thin film transistor panel and the opposing panel, in which thethin film transistor panel and the opposing panel are baked at differenttemperatures, respectively; forming a liquid crystal layer and bondingthe thin film transistor panel and the opposing panel; and exposing thebonded panels to an ultraviolet ray electric field.
 16. The method ofclaim 15, wherein: a difference between a pretilt angle provided by thealignment layer on the thin film transistor panel and a pretilt angleprovided by the alignment layer on the opposing panel is equal to orgreater than about 0.8 degree.
 17. The method of claim 16, wherein: theapplying the alignment material includes applying a same alignmentmaterial including reactive mesogen onto each of the thin filmtransistor panel and the opposing panel.
 18. The method of claim 17,wherein: the forming the alignment layers includes differentiatingpre-curing temperatures for the alignment materials of the thin filmtransistor panel and the opposing panel, respectively.
 19. The method ofclaim 17, wherein: the forming the alignment layers includesdifferentiating main-curing temperatures for the alignment materials ofthe thin film transistor panel and the opposing panel, respectively. 20.The method of claim 17, wherein: the forming the alignment layersincludes differentiating pre-curing temperatures and main-curingtemperatures for the alignment materials of the thin film transistorpanel and the opposing panel, respectively.
 21. The method of claim 17,wherein: the alignment material applied onto the opposing panel issubjected to pre-curing at a lower temperature than that of thealignment material applied onto the thin film transistor panel.
 22. Themethod of claim 17, wherein: the alignment material applied onto theopposing panel is subjected to main-curing at a higher temperature thanthat of the alignment material applied onto the thin film transistorpanel.
 23. The method of claim 15, wherein: the alignment layers includean alignment adjusting layer and a pretilt adjusting layer.
 24. Themethod of claim 15, further comprising: exposing only one panel amongthe thin film transistor and opposing panels to ultraviolet rays beforethe forming the liquid crystal layer and the bonding the thin filmtransistor panel and an opposing panel.